The present invention relates to industrial finishing equipment and particularly to a composite tank for use with industrial finishing equipment. More particularly, the present invention relates to a composite tank that can be used in an industrial washer or an industrial rinse machine such as a post rinse machine that is installed in-line following an electrodeposition coating station, the tank resisting the corrosive effects of chemicals such as deionized water often found in rinsing operations for rinsing work pieces.
It is well known that cleaning and rinsing solutions used in industrial finishing equipment, including deionized water (DI water), can corrode metal parts exposed to the solution. In response, manufacturers of industrial finishing equipment have replaced many metal parts with replacement parts made from corrosion resistant materials such as stainless steel. Manufacturers have also coated exposed metal parts with corrosion resistant coatings such as plastics materials and fiberglass reinforced plastics to protect the parts against corrosion. For example, U.S. Pat. No. 5,108,554 to Deters discloses that such corrosive resistant coatings may include a zinc layer applied by electroplating, a chromate layer over the zinc, and a final coating with a synthetic resin.
What is needed is a tank for use in industrial finishing equipment that is inexpensive and easy to manufacture and yet can withstand exposure to corrosive chemicals without deteriorating. In addition, manufacturers and users of such industrial finishing equipment would appreciate such a low-cost tank having a construction that would permit the tank to have an odd-shaped or custom-shaped "foot print" so that the tank can be installed in a location requiring the tank to have a non-rectangular shape.
According to the present invention, a composite tank for use with industrial finishing equipment is provided. The tank includes a generally planar bottom plate. Wall panels made from fiberglass reinforced plastic are attached to the bottom plate and extend generally upwardly therefrom so that the wall panels cooperate with the bottom plate to define an interior region of the tank. The upwardly-facing surface of the bottom plate and portions of the wall panels adjacent to the bottom plate are coated with fiberglass reinforced plastic to provide the tank with a seamless and water impermeable interior.
In preferred embodiments, the tank includes a generally planar bottom plate made from a material providing structural support for the tank and acting as a substrate for the fiberglass reinforced plastic (FRP). Preferably, the bottom plate is sloped so that particulates and debris in the solution carried by the tank will tend to settle adjacent to the downward portion of the bottom plate. The bottom plate includes a plurality of generally straight edges defining the perimeter of the bottom plate.
A plurality of generally planar wall panels made from FRP are attached to the bottom plate. The bottom plate is formed to include a perimetral edge including a plurality of generally straight edges and each wall panel is positioned to lie against a straight edge on the perimeter of the bottom plate. If desired, in the case of a particularly lengthy bottom plate edge, wall panels can be placed side-by-side along the edge to accommodate the lengthy side of the tank. The bottom plate cooperates with the wall panels to define an interior region of the tank.
The bottom plate is preferably coated with FRP and the wall panels are preferably "glassed" to one another and to the bottom plate by applying FRP to the bottom plate, to the bottoms of the wall panels adjacent to the bottom plate, and to the seams between adjacent wall panels so that the inside of the tank is seamless. Coating the bottom plate with FRP and providing the tank with the seamless construction allows for construction of the tank including a bottom plate made from a number of materials such as stainless steel, black iron, wood, or any other suitable material that will provide a substrate for holding the FRP.
If desired, the bottom plate can be made from a foam material, such as isocyanurate-polyurethane foam commonly used as insulation material (hereinafter foam), so that the bottom plate can be easily shaped. For example, a foam bottom plate can be formed in the shape of a wedge so that a bottom of the wedge which defines the outside bottom wall of the tank is generally horizontal and the top of the wedge, which defines the inside bottom wall of the interior region of the tank, is sloped.
The bottom plate can also be shaped to provide the tank with an odd-shaped "foot print" so that the positioning of the tank can be customized to match the floor space limitations of the installation site. For example, if the bottom plate is L-shaped, then the plurality of wall panels attached to the bottom plate will include a minimum of six wall panels so that the tank has a generally L-shaped footprint. It can be seen that the bottom plate can be any of a number of shapes including being square, rectangular, T-shaped, and any other shape of practical significance that can be made using generally straight sides.
Additional objects, features, and advantages of the invention will become apparent to those skilled in the art upon consideration of the following detailed description of preferred embodiments exemplifying the best mode of carrying out the invention as presently perceived.